Due to their composition, cosmetic agents can be a culture medium for germs and microorganisms. These germs can lead on the one hand to a microbial contamination of the consumer, and on the other hand can modify ingredients of the cosmetics and thus form substances that have undesirable effects, such as sensitization or skin irritation. In order to prevent these undesirable effects and in order to ensure a certain minimum shelf life of the cosmetics, these must be preserved. Since preservatives in turn have the potential to cause irritation, their use in cosmetics is strictly regulated.
The skin microflora has a key influence on the different cosmetic parameters. Pathogenic germs, such as Staphylococcus aureus thus play a key role in the development of skin blemishes. The most recent studies also indicate that an unbalanced skin microflora can have an influence on skin ageing, since undesirable germs lead to an increased immune response of the skin, which in turn leads to increased inflammatory reactions, during the course of which skin ageing markers are stimulated.
It is therefore desirable to provide preservative compositions which on the one hand prevent the population of the product or the skin with undesirable germs and on the other hand do not or do not significantly interfere with the natural skin flora.
The mixing of various antimicrobial substances in order to increase the antimicrobial activity is known in principle. Document WO 03/043593 A1 proposes combining conventional antibacterial substances, such as triclosan, phenoxyethanol or hexetidine, with ethyl lauroyl arginate in order to increase the antimicrobial effect. In WO 2007/014580 A1, preservative mixtures are proposed which, in addition to ethyl lauroyl arginate, also include salts of organic or inorganic acids, sodium citrate, sodium acetate, sodium glutamate, sodium fumarate, sodium malate, sodium gluconate, sodium laurate, sodium lactate, sodium hexametaphosphate, sodium-tert-butyl-hydroquinone, sodium propylparabenate or the hydrochlorides of glucosamine or ethanolamine. Cosmetic compositions which include a preservative mixture formed from ethyl lauroyl arginate and parabenes, imidazolyl urea, phenoxyethanol, DMDM hydantoin, 2-methyl-5-chlor-3,4-isothiazolinone/2-methyl-3,4-isothiazolinone and Quaternium-15 are disclosed in EP 1414394 B1.
There is thus also a need to provide antimicrobial compositions which are highly effective in small use quantities.
To summarize, it is desirable to provide cleaning compositions which have an excellent cleaning and caring effect alongside good preservation. In particular, synergistic preservative mixtures should be discovered which are highly effective at low concentrations and which, on account of reduced use quantities on the whole, enable the preparation of cleaning compositions that cause little irritation and sensitization. Furthermore, no preservatives considered by consumers to be critical should be used. In addition, the foam quality, foam quantity and foam volume should not be negatively influenced by the addition of the preservative mixture.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with this background of the invention.